Current specifications for the wireless system standardized by the members of the 3rd-Generation Partnership (3GPP) and referred to as “Long Term Evolution of UMTS (LTE)” (LTE) allow a wireless communication device to modify the uplink transmission timing in response to a detected change in serving cell downlink timing, provided that such modifications are carried out gradually according to rules specified in 3GPP TS 36.133 V12.7.0, Section 7.1.2. For example, for non-initial transmission and an LTE bandwidth of 1.4 MHz (minimum sample rate 1.92 MS/s):                maximum timing adjustment in one correction shall not exceed 17.5 TS (0.6 μs),        minimum aggregated adjustment rate shall be 7 TS (0.2 μs) per second, and        maximum aggregated adjustment rate shall be 17.5 TS (0.6 μs) per 200 milliseconds (ms).The network node may send timing advance commands (TACs) to the wireless communication device to adjust the uplink transmission timing in order to have the uplink signals arrive at the network node receiver at the desirable point in time.        
When wireless communication devices operate in a coverage enhancement mode, wherein the coverage enhancement is provided by message repetition, the timing advance control loop latency becomes longer than in conventional LTE system operation. This is because the uplink reference signals from multiple subframes may have to be averaged or filtered by the network node, to determine channel estimates from which the misalignment with respect to the desirable signal reception time can be determined. Additionally, when a half-duplex frequency-division duplexing (HD-FDD) configuration is used by the wireless communication device (e.g., in HD-FDD eMTC and/or NB-IoT devices), the network node has fewer opportunities to send TACs to the device. Particularly, during an uplink transmission period, the wireless communication device operating in HD-FDD configuration will not listen to the downlink and therefore is out of reach for the network node until tuning back to a downlink reception period.
As it is unspecified how and when the wireless communication device will adjust its timing when operating in enhanced coverage and in particular when uplink signals are transmitted with a certain number of repetitions, the existing rules in 3GPP TS 36.133 V12.7.0, Section 7.1.2 cannot be applied for any device (e.g., eMTC, NB-IoT devices etc) that is operating in an enhanced coverage mode and employing repetitions of the uplink signal transmission.